ISO 21741:2020
(Main)Stationary source emissions — Sampling and determination of mercury compounds in flue gas using gold amalgamation trap
Stationary source emissions — Sampling and determination of mercury compounds in flue gas using gold amalgamation trap
This document describes a method for the sampling and measurement of mercury of both vapour and solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg0) and oxidized (Hg2+) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous) mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after removing solid-phase (particulate) mercury with a filter. Because gold amalgamation trap captures only gaseous elemental mercury, the oxidized mercury (Hg2+) in the vapour phase is converted to elemental mercury (Hg0) prior to the gold amalgamation trap. The concentration of gaseous mercury is determined using atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS) after releasing mercury by heating the gold amalgamation trap. Separately, particulate mercury is collected isokinetically on a filter and the concentration is determined using cold vapour AAS or cold vapour AFS after dissolving the particulate mercury into solution. The total concentration of mercury in flue gas is expressed as the sum of both gaseous and particulate mercury concentrations. The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury ranging from 0,01 μg/m3 to 100 μg/m3 with sampling volumes from 0,005 m3 to 0,1 m3 and sample gas flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically from 0,01 μg/m3 to 100 μg/m3 with sampling volume from 0,05 m3 to 1 m3.
Émissions de sources fixes — Échantillonnage et détermination de la teneur en mercure dans les gaz de combustion en utilisant un piège d’amalgamation avec de l’or
Le présent document décrit une méthode de prélèvement et de mesurage du mercure en phase vapeur et en phase solide dans les effluents gazeux des sources fixes. Le mercure existe généralement sous forme élémentaire (Hg0) et oxydée (Hg2+), à la fois en phase vapeur et en phase solide, dans les effluents gazeux. Le mercure en phase vapeur (gazeux) est collecté par échantillonnage isocinétique ou non isocinétique avec un piège d'amalgamation composé d'or après élimination du mercure en phase solide (particulaire) à l'aide d'un filtre. Le piège d'amalgamation avec de l'or collectant uniquement le mercure élémentaire gazeux, le mercure oxydé (Hg2+) est converti en mercure élémentaire (Hg0) en phase vapeur, avant le piège d'amalgamation. La concentration en mercure gazeux est déterminée par spectrométrie d'absorption atomique (AAS) ou par spectrométrie de fluorescence atomique (AFS) après relargage du mercure par chauffage du piège d'amalgamation avec de l'or. Parallèlement, le mercure particulaire est collecté par échantillonnage isocinétique sur un filtre et sa concentration est déterminée par spectrométrie d'absorption atomique à vapeur froide (CVAAS) ou par spectrométrie de fluorescence atomique à vapeur froide (CVAFS) après mise en solution du mercure particulaire. La concentration totale en mercure dans l'effluent gazeux est exprimée sous forme de somme des concentrations en mercure gazeux et en mercure particulaire. La méthode d'amalgamation avec de l'or est destinée aux mesurages à court terme (périodiques) du mercure gazeux dans une plage de concentration de 0,01 μg/m3 à 100 μg/m3 avec des volumes de prélèvement compris entre 0,005 m3 et 0,1 m3 et un débit de gaz prélevé compris entre 0,2 l/min et 1 l/min. La plage de mesurage du mercure particulaire s'étend généralement de 0,01 μg/m3 à 100 μg/m3 avec des volumes de prélèvement compris entre 0,05 m3 et 1 m3.
Emisije nepremičnih virov - Vzorčenje in določevanje živosrebrovih spojin v odpadnih plinih z amalgamacijo na zlatih pasteh
General Information
Buy Standard
Standards Content (Sample)
SLOVENSKI STANDARD
SIST ISO 21741:2021
01-maj-2021
Emisije nepremičnih virov - Vzorčenje in določevanje živosrebrovih spojin v
odpadnih plinih z amalgamacijo na zlatih pasteh
Stationary source emissions - Sampling and determination of mercury compounds in flue
gas using gold amalgamation trap
Émissions de sources fixes - Échantillonnage et détermination de la teneur en mercure
dans les gaz de combustion en utilisant un piège d’amalgamation de l’or
Ta slovenski standard je istoveten z: ISO 21741:2020
ICS:
13.040.40 Emisije nepremičnih virov Stationary source emissions
SIST ISO 21741:2021 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST ISO 21741:2021
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SIST ISO 21741:2021
INTERNATIONAL ISO
STANDARD 21741
First edition
2020-11
Stationary source emissions —
Sampling and determination of
mercury compounds in flue gas using
gold amalgamation trap
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en mercure dans les gaz de combustion en utilisant un piège
d’amalgamation de l’or
Reference number
ISO 21741:2020(E)
©
ISO 2020
---------------------- Page: 3 ----------------------
SIST ISO 21741:2021
ISO 21741:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
SIST ISO 21741:2021
ISO 21741:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 2
4.1 Symbols . 2
4.2 Abbreviated terms . 4
5 Principle . 4
6 Reagents . 4
6.1 General . 4
6.2 Water . 5
6.3 Nitric acid . 5
6.4 Sulfuric acid . 5
6.5 Stannous chloride solution . 5
6.6 Phosphate buffer solution . 5
6.7 Hydrofluoric acid . 5
6.8 Hydrochloric acid . 5
6.9 Mercury stock solution . 5
6.10 Rinse solution . 5
6.11 Sample gas drying agent . 5
6.12 Trapping agent of mercury . 6
7 Apparatus . 6
7.1 General . 6
7.1.1 Main-stream sampling . 6
7.1.2 Side-stream sampling . 8
7.2 Nozzle. 9
7.3 Filter and filter housing . 9
7.4 Transfer line .10
7.5 Pretreatment unit .10
7.6 Gold amalgamation trap.11
7.7 Drying unit .11
7.8 Suction unit .11
7.9 Thermometer .11
7.10 Manometer .12
7.11 Gas meter .12
7.12 Flowmeter .12
7.13 Barometer .12
8 Sampling .12
8.1 General .12
8.2 Sampling position and sampling point .12
8.3 Sampling duration and sample volume .12
8.4 Other measurements to be made prior to sampling .13
8.4.1 Volumetric gas flow through duct at the sampling plane .13
8.4.2 Moisture content of gas .13
8.4.3 Oxygen content of gas .13
8.5 Assembly of sampling apparatus .13
8.6 Sampling .13
8.7 Checking for leaks .14
8.8 Quality assurance.14
8.9 Sample recovery .14
© ISO 2020 – All rights reserved iii
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SIST ISO 21741:2021
ISO 21741:2020(E)
8.10 Reagent blank.15
8.11 Field blank .15
9 Sample preparation .15
9.1 General .15
9.2 Sample preparation for particulate mercury analysis .15
10 Analytical procedure .16
10.1 Analytical procedure for mercury collected with gold amalgamation trap .16
10.2 Analytical procedure for mercury in rinse solution and digested solution .17
11 Expression of results .17
11.1 Calculation of the volume of dry flue gas sampled at sampling conditions .17
11.2 Calculation of the volume of dry flue gas sample normalized to standard
temperature and pressure .18
11.3 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP .18
11.4 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP and reference oxygen volume fraction .20
11.5 Rate of mass discharge of mercury expressed as elemental mercury .20
11.6 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP .20
11.7 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP and reference oxygen concentration .21
12 Performance characteristics .21
12.1 Detection limits .21
12.2 Evaluation of measurement uncertainty .21
13 Test report .22
Annex A (informative) Preparation of mercury reference gas .24
Annex B (informative) Results of evaluation of measurement uncertainties.27
Annex C (informative) Comparison of analytical results obtained with heated solid catalytic
reduction unit and stannous chloride solution unit .29
Annex D (informative) Comparison of analytical results obtained with this method and
EN 13211 .31
Annex E (informative) Interference from sulfur dioxide (SO ) on the recovery of elemental
2
mercury and oxidized mercury .33
Bibliography .35
iv © ISO 2020 – All rights reserved
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SIST ISO 21741:2021
ISO 21741:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,
Stationary source emissions.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
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SIST ISO 21741:2021
ISO 21741:2020(E)
Introduction
Because mercury is exhausted from stationary sources such as coal combustion plants, cement kilns,
non-ferrous metal smelting operations and roasting plants, and waste incineration facilities, the
monitoring of the stationary source mercury mass emissions is increasingly important for preventing
global environmental pollution and health damage caused by mercury.
This document describes a method for the sampling and determination of mercury concentrations
0
in a flue gas passing through ducts or chimney stacks. Mercury generally exists as elemental (Hg )
2+
and oxidized (Hg ) forms, both in vapour and in solid phases in flue gases, this method allows the
determination of both total vapour-phase mercury and total solid-phase mercury concentrations in
flue gases.
vi © ISO 2020 – All rights reserved
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SIST ISO 21741:2021
INTERNATIONAL STANDARD ISO 21741:2020(E)
Stationary source emissions — Sampling and
determination of mercury compounds in flue gas using
gold amalgamation trap
1 Scope
This document describes a method for the sampling and measurement of mercury of both vapour and
0
solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg ) and
2+
oxidized (Hg ) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous)
mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after
removing solid-phase (particulate) mercury with a filter. Because gold amalgamation trap captures
2+
only gaseous elemental mercury, the oxidized mercury (Hg ) in the vapour phase is converted to
0
elemental mercury (Hg ) prior to the gold amalgamation trap. The concentration of gaseous mercury
is determined using atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS)
after releasing mercury by heating the gold amalgamation trap. Separately, particulate mercury is
collected isokinetically on a filter and the concentration is determined using cold vapour AAS or cold
vapour AFS after dissolving the particulate mercury into solution.
The total concentration of mercury in flue gas is expressed as the sum of both gaseous and particulate
mercury concentrations.
The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury
3 3 3 3
ranging from 0,01 μg/m to 100 μg/m with sampling volumes from 0,005 m to 0,1 m and sample gas
flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically
3 3 3 3
from 0,01 μg/m to 100 μg/m with sampling volume from 0,05 m to 1 m .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 9096, Stationary source emissions — Manual determination of mass concentration of particulate matter
ISO 10396, Stationary source emissions — Sampling for the automated determination of gas emission
concentrations for permanently-installed monitoring systems
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter
(dust) at low concentrations — Manual gravimetric method
ISO 12846:2012, Water quality — Determination of mercury — Method using atomic absorption
spectrometry (AAS) with and without enrichment
ISO 16911-1, Stationary source emissions — Manual and automatic determination of velocity and volume
flow rate in ducts — Part 1: Manual reference method
ISO 17852:2006, Water quality — Determination of mercury — Method using atomic fluorescence
spectrometry
ISO 20988, Air quality — Guidelines for estimating measurement uncertainty
© ISO 2020 – All rights reserved 1
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SIST ISO 21741:2021
ISO 21741:2020(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
gaseous mercury
mercury existing both as elemental and oxidized forms passing through a filter having at least 99,5 %
collection efficiency for 0,3 μm diameter particles
3.2
particulate mercury
mercury existing both as elemental and oxidized forms contained in a solid phase particle collected by
a filter having at least 99,5 % collection efficiency for 0,3 μm diameter particles
3.3
isokinetic sampling
sampling at a flow rate such that the velocity and direction of the gas entering the sampling nozzle are
the same as those of the gas in the duct at the sampling point (3.4)
3.4
sampling point
specific position on the sampling section at which a sample is extracted
3.5
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Symbols and abbreviated terms
4.1 Symbols
M amounts of mercury in the first gold amalgamation trap (μg)
A1,Hg
M amounts of mercury in the second gold amalgamation trap (μg)
A2,Hg
C concentration of mercury in a prepared sample of rinse solution that washed the transfer
R,Hg
line from the filter housing to the impinger nozzle of stannous chloride solution or the inlet
of catalytic reduction unit in main-stream sampling (μg/ml). Ref. Figure 1 and 2.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R1,Hg
from the filter housing to the T-piece in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R2,Hg
after the T-piece to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample solution for particulate mercury
S,Hg
analysis (μg/ml)
d density of reagent solution (g/ml)
p atmospheric pressure (kPa)
atm
2 © ISO 2020 – All rights reserved
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SIST ISO 21741:2021
ISO 21741:2020(E)
p average pressure difference between the sample gas before the gas meter and the
av
atmosphere (kPa)
q rate of mass discharge of mercury expressed as elemental mercury (mg/s)
m,Hg
q volume flow rate of flue gas through the sampling plane at conditions i of temperature,
V,fg,i
3
pressure, moisture and oxygen content (m /s)
T average temperature of the sample gas before the gas meter (K)
av
3
u(y) standard uncertainty (μg/m )
3
V volume of dry flue gas sample normalized to STP (m )
d
3
V final gas meter reading at the end of sampling (m )
f
3
V volume of dry flue gas sample for gaseous mercury analysis normalized to STP (m )
G,d
3
V initial gas meter reading at the beginning of sampling (m )
i
3
V volume of air drawn through the gas meter during any intermediate leak tests (m )
l
3
V volume of dry flue gas sample (m )
m
V volume of dry flue gas sample in main stream, normalized to STP, in side-stream
main,d
3
sampling (m )
3
V volume of dry flue gas sample for particulate mercury analysis normalized to STP (m )
S,d
V volume of dry flue gas sampled in side stream, normalized to STP, in side-stream
side,d
3
sampling (m )
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R
housing to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in main-stream sampling (ml). Ref. Figure 1 and 2.
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R1
housing to the T-piece in side-stream sampling (ml). Ref. Figure 3.
v volume of a recovered sample of rinse solution that washed transfer line after the T-piece to
R2
the impinger nozzle of stannous chloride solution or the inlet of catalytic reduction unit in
side-stream sampling (ml). Ref. Figure 3.
v volume of a prepared sample solution for particulate mercury analysis (ml)
S
w average moisture content of the flue gas at the sampling plane during the sampling period (%)
W
3
y j th concentration value of the first measuring system (μg/m )
1,j
3
y j th concentration value of the second measuring system (μg/m )
2,j
ρ mass concentration of gaseous mercury expressed as elemental mercury in the flue gas on a
G,Hg,dry
3
dry basis at STP (μg/m )
ρ mass concentration of particulate mercury expressed as elemental mercury in the flue gas
S,Hg,dry
3
on a dry basis at STP (μg/m )
ρ mass concentration of total mercury expressed as elemental mercury in the flue gas on
Hg,dry
3
a dry basis at STP (μg/m )
© ISO 2020 – All rights reserved 3
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SIST ISO 21741:2021
ISO 21741:2020(E)
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a dry
Hg,dry,O
3
basis at STP and reference oxygen concentration (μg/m )
ρ mass concentration of mercury expressed as elemental mercury at conditions i of
Hg,i
3
temperature, pressure, oxygen and moisture conditions (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet
3
basis at STP (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet,O
3
basis at STP and reference oxygen concentration (μg/m )
φ volume fraction of the oxygen on a dry basis measured during the
...
INTERNATIONAL ISO
STANDARD 21741
First edition
2020-11
Stationary source emissions —
Sampling and determination of
mercury compounds in flue gas using
gold amalgamation trap
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en mercure dans les gaz de combustion en utilisant un piège
d’amalgamation de l’or
Reference number
ISO 21741:2020(E)
©
ISO 2020
---------------------- Page: 1 ----------------------
ISO 21741:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO 21741:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 2
4.1 Symbols . 2
4.2 Abbreviated terms . 4
5 Principle . 4
6 Reagents . 4
6.1 General . 4
6.2 Water . 5
6.3 Nitric acid . 5
6.4 Sulfuric acid . 5
6.5 Stannous chloride solution . 5
6.6 Phosphate buffer solution . 5
6.7 Hydrofluoric acid . 5
6.8 Hydrochloric acid . 5
6.9 Mercury stock solution . 5
6.10 Rinse solution . 5
6.11 Sample gas drying agent . 5
6.12 Trapping agent of mercury . 6
7 Apparatus . 6
7.1 General . 6
7.1.1 Main-stream sampling . 6
7.1.2 Side-stream sampling . 8
7.2 Nozzle. 9
7.3 Filter and filter housing . 9
7.4 Transfer line .10
7.5 Pretreatment unit .10
7.6 Gold amalgamation trap.11
7.7 Drying unit .11
7.8 Suction unit .11
7.9 Thermometer .11
7.10 Manometer .12
7.11 Gas meter .12
7.12 Flowmeter .12
7.13 Barometer .12
8 Sampling .12
8.1 General .12
8.2 Sampling position and sampling point .12
8.3 Sampling duration and sample volume .12
8.4 Other measurements to be made prior to sampling .13
8.4.1 Volumetric gas flow through duct at the sampling plane .13
8.4.2 Moisture content of gas .13
8.4.3 Oxygen content of gas .13
8.5 Assembly of sampling apparatus .13
8.6 Sampling .13
8.7 Checking for leaks .14
8.8 Quality assurance.14
8.9 Sample recovery .14
© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO 21741:2020(E)
8.10 Reagent blank.15
8.11 Field blank .15
9 Sample preparation .15
9.1 General .15
9.2 Sample preparation for particulate mercury analysis .15
10 Analytical procedure .16
10.1 Analytical procedure for mercury collected with gold amalgamation trap .16
10.2 Analytical procedure for mercury in rinse solution and digested solution .17
11 Expression of results .17
11.1 Calculation of the volume of dry flue gas sampled at sampling conditions .17
11.2 Calculation of the volume of dry flue gas sample normalized to standard
temperature and pressure .18
11.3 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP .18
11.4 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP and reference oxygen volume fraction .20
11.5 Rate of mass discharge of mercury expressed as elemental mercury .20
11.6 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP .20
11.7 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP and reference oxygen concentration .21
12 Performance characteristics .21
12.1 Detection limits .21
12.2 Evaluation of measurement uncertainty .21
13 Test report .22
Annex A (informative) Preparation of mercury reference gas .24
Annex B (informative) Results of evaluation of measurement uncertainties.27
Annex C (informative) Comparison of analytical results obtained with heated solid catalytic
reduction unit and stannous chloride solution unit .29
Annex D (informative) Comparison of analytical results obtained with this method and
EN 13211 .31
Annex E (informative) Interference from sulfur dioxide (SO ) on the recovery of elemental
2
mercury and oxidized mercury .33
Bibliography .35
iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO 21741:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,
Stationary source emissions.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO 21741:2020(E)
Introduction
Because mercury is exhausted from stationary sources such as coal combustion plants, cement kilns,
non-ferrous metal smelting operations and roasting plants, and waste incineration facilities, the
monitoring of the stationary source mercury mass emissions is increasingly important for preventing
global environmental pollution and health damage caused by mercury.
This document describes a method for the sampling and determination of mercury concentrations
0
in a flue gas passing through ducts or chimney stacks. Mercury generally exists as elemental (Hg )
2+
and oxidized (Hg ) forms, both in vapour and in solid phases in flue gases, this method allows the
determination of both total vapour-phase mercury and total solid-phase mercury concentrations in
flue gases.
vi © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
INTERNATIONAL STANDARD ISO 21741:2020(E)
Stationary source emissions — Sampling and
determination of mercury compounds in flue gas using
gold amalgamation trap
1 Scope
This document describes a method for the sampling and measurement of mercury of both vapour and
0
solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg ) and
2+
oxidized (Hg ) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous)
mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after
removing solid-phase (particulate) mercury with a filter. Because gold amalgamation trap captures
2+
only gaseous elemental mercury, the oxidized mercury (Hg ) in the vapour phase is converted to
0
elemental mercury (Hg ) prior to the gold amalgamation trap. The concentration of gaseous mercury
is determined using atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS)
after releasing mercury by heating the gold amalgamation trap. Separately, particulate mercury is
collected isokinetically on a filter and the concentration is determined using cold vapour AAS or cold
vapour AFS after dissolving the particulate mercury into solution.
The total concentration of mercury in flue gas is expressed as the sum of both gaseous and particulate
mercury concentrations.
The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury
3 3 3 3
ranging from 0,01 μg/m to 100 μg/m with sampling volumes from 0,005 m to 0,1 m and sample gas
flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically
3 3 3 3
from 0,01 μg/m to 100 μg/m with sampling volume from 0,05 m to 1 m .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 9096, Stationary source emissions — Manual determination of mass concentration of particulate matter
ISO 10396, Stationary source emissions — Sampling for the automated determination of gas emission
concentrations for permanently-installed monitoring systems
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter
(dust) at low concentrations — Manual gravimetric method
ISO 12846:2012, Water quality — Determination of mercury — Method using atomic absorption
spectrometry (AAS) with and without enrichment
ISO 16911-1, Stationary source emissions — Manual and automatic determination of velocity and volume
flow rate in ducts — Part 1: Manual reference method
ISO 17852:2006, Water quality — Determination of mercury — Method using atomic fluorescence
spectrometry
ISO 20988, Air quality — Guidelines for estimating measurement uncertainty
© ISO 2020 – All rights reserved 1
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ISO 21741:2020(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
gaseous mercury
mercury existing both as elemental and oxidized forms passing through a filter having at least 99,5 %
collection efficiency for 0,3 μm diameter particles
3.2
particulate mercury
mercury existing both as elemental and oxidized forms contained in a solid phase particle collected by
a filter having at least 99,5 % collection efficiency for 0,3 μm diameter particles
3.3
isokinetic sampling
sampling at a flow rate such that the velocity and direction of the gas entering the sampling nozzle are
the same as those of the gas in the duct at the sampling point (3.4)
3.4
sampling point
specific position on the sampling section at which a sample is extracted
3.5
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Symbols and abbreviated terms
4.1 Symbols
M amounts of mercury in the first gold amalgamation trap (μg)
A1,Hg
M amounts of mercury in the second gold amalgamation trap (μg)
A2,Hg
C concentration of mercury in a prepared sample of rinse solution that washed the transfer
R,Hg
line from the filter housing to the impinger nozzle of stannous chloride solution or the inlet
of catalytic reduction unit in main-stream sampling (μg/ml). Ref. Figure 1 and 2.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R1,Hg
from the filter housing to the T-piece in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R2,Hg
after the T-piece to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample solution for particulate mercury
S,Hg
analysis (μg/ml)
d density of reagent solution (g/ml)
p atmospheric pressure (kPa)
atm
2 © ISO 2020 – All rights reserved
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ISO 21741:2020(E)
p average pressure difference between the sample gas before the gas meter and the
av
atmosphere (kPa)
q rate of mass discharge of mercury expressed as elemental mercury (mg/s)
m,Hg
q volume flow rate of flue gas through the sampling plane at conditions i of temperature,
V,fg,i
3
pressure, moisture and oxygen content (m /s)
T average temperature of the sample gas before the gas meter (K)
av
3
u(y) standard uncertainty (μg/m )
3
V volume of dry flue gas sample normalized to STP (m )
d
3
V final gas meter reading at the end of sampling (m )
f
3
V volume of dry flue gas sample for gaseous mercury analysis normalized to STP (m )
G,d
3
V initial gas meter reading at the beginning of sampling (m )
i
3
V volume of air drawn through the gas meter during any intermediate leak tests (m )
l
3
V volume of dry flue gas sample (m )
m
V volume of dry flue gas sample in main stream, normalized to STP, in side-stream
main,d
3
sampling (m )
3
V volume of dry flue gas sample for particulate mercury analysis normalized to STP (m )
S,d
V volume of dry flue gas sampled in side stream, normalized to STP, in side-stream
side,d
3
sampling (m )
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R
housing to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in main-stream sampling (ml). Ref. Figure 1 and 2.
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R1
housing to the T-piece in side-stream sampling (ml). Ref. Figure 3.
v volume of a recovered sample of rinse solution that washed transfer line after the T-piece to
R2
the impinger nozzle of stannous chloride solution or the inlet of catalytic reduction unit in
side-stream sampling (ml). Ref. Figure 3.
v volume of a prepared sample solution for particulate mercury analysis (ml)
S
w average moisture content of the flue gas at the sampling plane during the sampling period (%)
W
3
y j th concentration value of the first measuring system (μg/m )
1,j
3
y j th concentration value of the second measuring system (μg/m )
2,j
ρ mass concentration of gaseous mercury expressed as elemental mercury in the flue gas on a
G,Hg,dry
3
dry basis at STP (μg/m )
ρ mass concentration of particulate mercury expressed as elemental mercury in the flue gas
S,Hg,dry
3
on a dry basis at STP (μg/m )
ρ mass concentration of total mercury expressed as elemental mercury in the flue gas on
Hg,dry
3
a dry basis at STP (μg/m )
© ISO 2020 – All rights reserved 3
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ISO 21741:2020(E)
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a dry
Hg,dry,O
3
basis at STP and reference oxygen concentration (μg/m )
ρ mass concentration of mercury expressed as elemental mercury at conditions i of
Hg,i
3
temperature, pressure, oxygen and moisture conditions (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet
3
basis at STP (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet,O
3
basis at STP and reference oxygen concentration (μg/m )
φ volume fraction of the oxygen on a dry basis measured during the sampling (%)
O, d
φ volume fraction of the reference oxygen for the process (%)
O, ref
4.2 Abbreviated terms
AAS atomic absorption spectrometry
AFS atomic fluorescence spectrometry
FEP perfluoro(ethylene/propylene), tetrafluoroethylene/hexafluoropropylene
PFA perfluoroalkoxy alkane
PTFE polytetrafluoroethylene
5 Principle
In flue gases, mercury commonly exists in both the vapour phase and solid phase. In this method,
particulate mercury is captured on a filter, and gaseous mercury is captured on a gold amalgamation
trap. The total concentration of mercury in a flue gas is expressed as the sum of both concentrations.
To determine particulate mercury contents in a flue gas, a sample is taken isokinetically and particles
are collected on a filter in accordance with ISO 9096 or ISO 12141. The particulate mercury on the filter
is dissolved into solution from the filter and the mercury concentration is determined using cold vapour
atomic absorption spectrometry (CV AAS, ISO 12846) or cold vapour atomic fluorescence spectrometry
(CV A
...
Style Definition
ISO/TC 146/SC 1 .
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Date : 2020-11: 2021-01
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ISO 21741:20202021(F)
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ISO/TC 146/SC 1
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Secrétariat : BIS
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Émissions de sources fixes — Échantillonnage et détermination de la teneur en
(France)
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mercure dans les gaz de combustion en utilisant un piège d’amalgamation avec de
Asian text, Don't adjust space between Asian text and
l’or
numbers
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Stationary source emissions — Sampling and determination of mercury compounds in flue
Formatted
...
gas using gold amalgamation trap
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ICS : 13.040.40
(France)
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Formatted: French (France)
Type du document : Norme internationale
Sous-type du document :
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Langue du document : F
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ISO 21741:20202021(F)
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ISO 21741:20202021(F)
Sommaire Page
Avant-propos 7
Introduction 8
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 2
4 Symboles et termes abrégés . 3
4.1 Symboles . 3
4.2 Abréviations . 5
5 Principe . 5
6 Réactifs . 6
6.1 Généralités. 6
6.2 Eau . 6
6.3 Acide nitrique . 7
6.4 Acide sulfurique . 7
6.5 Solution de chlorure stanneux . 7
6.6 Solution tampon phosphatée . 7
6.7 Acide fluorhydrique . 7
6.8 Acide chlorhydrique . 7
6.9 Solution mère de mercure . 7
6.10 Solution de rinçage . 7
6.11 Agent de déshydratation du gaz prélevé . 8
6.12 Agent de piégeage du mercure . 8
7 Appareillage . 8
7.1 Généralités. 8
7.1.1 Système de prélèvement sans ligne secondaire. 9
7.1.2 Système de prélèvement avec ligne secondaire . 11
7.2 Buse . 13
7.3 Filtre et porte-filtre . 13
7.4 Ligne de transfert . 13
7.5 Unité de prétraitement . 14
7.6 Piège d’amalgamation avec de l’or . 14
7.7 Unité de séchage . 15
7.8 Pompe de prélèvement . 15
7.9 Thermomètre . 15
7.10 Manomètre . 16
7.11 Compteur à gaz . 16
7.12 Débitmètre . 16
7.13 Baromètre . 16
8 Prélèvement . 16
8.1 Généralités. 16
8.2 Position et point de prélèvement . 16
8.3 Durée de prélèvement et volume prélevé . 16
8.4 Autres mesurages à effectuer avant le prélèvement . 17
8.4.1 Débit-volume du gaz au niveau de la section de mesurage du conduit . 17
8.4.2 Teneur en vapeur d’eau du gaz . 17
© ISO 20202021 – Tous droits réservés
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ISO 21741:20202021(F)
8.4.3 Teneur en oxygène du gaz . 17
8.5 Assemblage de l’appareillage de prélèvement . 17
8.6 Prélèvement . 17
8.7 Contrôle d’étanchéité . 18
8.8 Assurance de la qualité . 18
8.9 Récupération de l’échantillon . 19
8.10 Blanc de réactif . 19
8.11 Blanc de site . 20
9 Préparation de l’échantillon . 20
9.1 Généralités . 20
9.2 Préparation de l’échantillon en vue de l’analyse du mercure particulaire . 20
10 Mode opératoire d’analyse . 20
10.1 Mode opératoire d’analyse applicable au mercure collecté avec le piège
d’amalgamation avec de l’or . 20
10.2 Mode opératoire d’analyse pour le mercure présent dans la solution de rinçage et la
solution digérée . 22
11 Expression des résultats . 23
11.1 Calcul du volume d’effluent gazeux sec prélevé dans les conditions de prélèvement . 23
11.2 Calcul du volume de l’échantillon sec d’effluent gazeux normalisé en fonction d’une
température normale et d’une pression normale . 23
11.3 Concentration massique de mercure gazeux dans l’effluent gazeux exprimé en
mercure élémentaire sur une base sèche et dans les conditions NTP . 23
11.4 Concentration massique de mercure dans l’effluent gazeux exprimé en mercure
élémentaire, sur une base sèche, dans les conditions NTP et avec une teneur en
oxygène de référence . 25
11.5 Flux massique du mercure exprimé en mercure élémentaire . 26
11.6 Concentration massique de mercure de l’effluent gazeux exprimé en mercure
élémentaire sur une base humide dans les conditions NTP . 26
11.7 Concentration massique de mercure de l’effluent gazeux exprimé en mercure
élémentaire de , sur une base humide dans les conditions NTP et avec une teneur en
oxygène de référence . 26
12 Caractéristiques de performances . 27
12.1 Limites de détection . 27
12.2 Évaluation de l’incertitude de mesure . 27
13 Rapport d’essai . 27
Annexe A (informative) Préparation du mercure gazeux de référence . 29
Annexe B (informative) Résultats de l’évaluation de l’incertitude de mesure. 33
Annexe C (informative) Comparaison des résultats analytiques obtenus en utilisant une
unité de réduction catalytique chauffée et une unité de solution de chlorure
stanneux . 36
Annexe D (informative) Comparaison des résultats analytiques obtenus en utilisant la
présente méthode et l’EN 13211 . 39
Annexe E (informative) Interférence du dioxyde de soufre (SO2) sur la récupération du
mercure élémentaire et du mercure oxydé . 41
Bibliographie . 44
© ISO 20202021 – Tous droits réservés
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ISO 21741:20202021(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude a le
droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2
(voir www.iso.org/directives).
L’attention est attirée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant les
références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www.iso.org/brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion
de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant : www.iso.org/iso/fr/avant-propos.
Le présent document a été élaboré par le comité technique ISO/TC 146, Qualité de l’air, sous--
comité SC 1, Émissions de sources fixes.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www.iso.org/fr/members.html.
© ISO 20202021 – Tous droits réservés
vi
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ISO 21741:20202021(F)
Introduction
Les sources fixes telles que les installations de combustion à charbon, les fours de cimenterie, les
activités de fonderie de métaux non ferreux, les installations de calcination et les installations
d’incinération de déchets émettent du mercure. Il est donc de plus en plus important de contrôler les
émissions massiques de mercure des sources fixes afin de prévenir la pollution environnementale et les
effets néfastes du mercure sur la santé.
Le présent document décrit une méthode de prélèvement et de détermination des concentrations en
mercure des effluents gazeux dans les conduits ou émis en cheminées d’usine. Le mercure existe
0 2+
généralement sous forme élémentaire (Hg ) et oxydée (Hg ), à la fois en phase vapeur et en phase
solide, dans les effluents gazeux. Cette méthode permet de déterminer les concentrations totales en
mercure en phase vapeur et les concentrations totales en mercure en phase solide dans les effluents
gazeux.
© ISO 20202021 – Tous droits réservés
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NORME INTERNATIONALE ISO 21741:20202021(F)
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Émissions de sources fixes — Échantillonnage et
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détermination de la teneur en mercure dans les gaz de
space between Latin and Asian text, Don't adjust space
between Asian text and numbers
combustion en utilisant un piège d’amalgamation avec de l’or
1 Domaine d’application Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers,
Tab stops: 0.76 cm, Left
Le présent document décrit une méthode de prélèvement et de mesurage du mercure en phase vapeur
Formatted: Don't adjust space between Latin and Asian
et en phase solide dans les effluents gazeux des sources fixes. Le mercure existe généralement sous
text, Don't adjust space between Asian text and numbers
0 2+
forme élémentaire (Hg ) et oxydée (Hg ), à la fois en phase vapeur et en phase solide, dans les effluents
gazeux. Le mercure en phase vapeur (gazeux) est collecté par échantillonnage isocinétique ou non
isocinétique avec un piège d’amalgamation composé d’or après élimination du mercure en phase solide
(particulaire) à l’aide d’un filtre. Le piège d’amalgamation avec de l’or collectant uniquement le mercure
2+ 0
élémentaire gazeux, le mercure oxydé (Hg ) est converti en mercure élémentaire (Hg ) en phase
vapeur, avant le piège d’amalgamation. La concentration en mercure gazeux est déterminée par
spectrométrie d’absorption atomique (AAS) ou par spectrométrie de fluorescence atomique (AFS)
après relargage du mercure par chauffage du piège d’amalgamation avec de l’or. Parallèlement, le
mercure particulaire est collecté par échantillonnage isocinétique sur un filtre et sa concentration est
déterminée par spectrométrie d’absorption atomique à vapeur froide (CVAAS) ou par spectrométrie de
fluorescence atomique à vapeur froide (CVAFS) après mise en solution du mercure particulaire.
La concentration totale en mercure dans l’effluent gazeux est exprimée sous forme de somme des
concentrations en mercure gazeux et en mercure particulaire.
La méthode d’amalgamation avec de l’or est destinée aux mesurages à court terme (périodiques) du
3 3
mercure gazeux dans une plage de concentration de 0,01 μg/m à 100 μg/m avec des volumes de
3 3
prélèvement compris entre 0,005 m et 0,1 m et un débit de gaz prélevé compris entre 0,2 l/min et
3
1 l/min. La plage de mesurage du mercure particulaire s’étend généralement de 0,01 μg/m à
3 3 3
100 μg/m avec des volumes de prélèvement compris entre 0,05 m et 1 m .
2 Références normatives Formatted: Tab stops: 0.76 cm, Left + Not at 0.71 cm
Les documents ci-après, dans leur intégralité ou non, sont des références normatives indispensables à Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers
l’application du présent document. Pour les références datées, seule l’édition citée s’applique. Pour les
références non datées, la dernière édition du document de référence s’applique (y compris les éventuels
amendements).
ISO 3696, Eau pour laboratoire à usage analytique — Spécification et méthodes d’essai.d'essai
ISO 9096, Émissions de sources fixes — Détermination manuelle de la concentration en masse de
poussières.
ISO 10396, Émissions de sources fixes — Échantillonnage pour la détermination automatisée des
concentrations d’émissiond'émission de gaz pour des systèmes fixes de surveillance.
ISO 12141, Émissions de sources fixes — Détermination d’uned'une faible concentration en masse de
matières particulaires (poussières) — Méthode gravimétrique manuelle.
Formatted: Default Paragraph Font
ISO 12846:2012, Qualité de l’eau l'eau — Dosage du mercure — Méthode par spectrométrie
d’absorptiond'absorption atomique (SAA) avec et sans enrichissement.
© ISO 20202021 – Tous droits réservés
1
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ISO 21741:20202021(F)
ISO 16911-1, Émissions de sources fixes — Détermination manuelle et automatique de la vitesse et du
débit-volume d’écoulementd'écoulement dans les conduits — Partie 1 : Méthode de référence manuelle.
ISO 17852:2006, Qualité de l’eau l'eau — Dosage du mercure — Méthode par spectrométrie de
fluorescence atomique.
ISO 20988, Qualité de l’air l'air — Lignes directrices pour estimer l’incertitudel'incertitude de mesure.
3 Termes et définitions Formatted: Tab stops: 0.76 cm, Left + Not at 0.71 cm
Pour les besoins du présent document, les termes et définitions suivants s’appliquent. Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes :
— ISO Online browsing platform : disponible à l’adresse https://www.iso.org/obp ;
— IEC Electropedia : disponible à l’adresse http://www.electropedia.org/.
3.1
mercure gazeux
mercure existant à la fois sous forme élémentaire et oxydée, traversant un filtre ayant un rendement de
collecte d’au moins 99,5 % pour des particules de 0,3 μm de diamètre
3.2
mercure particulaire
mercure existant à la fois sous forme élémentaire et oxydée, contenu dans une particule en phase solide
captée par un filtre ayant un rendement de collecte d’au moins 99,5 % pour des particules de 0,3 μm de
diamètre
3.3
échantillonnage isocinétique
prélèvement effectué à un débit tel que la vitesse et la direction du gaz entrant dans la buse de
prélèvement sont les mêmes que celles du gaz dans le conduit au niveau du point de prélèvement (3.4)
Formatted: Font: Not Italic
3.4
point de prélèvement
position spécifique sur la section de mesurage au niveau de laquelle un échantillon est extrait
3.5
NTP
conditions normales de température (273,15 K) et de pression (101,325 kPa)
4 Symboles et termes abrégés Formatted: Don't adjust space between Latin and Asian
text, Don't adjust space between Asian text and numbers,
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ISO 21741:20202021(F)
4.1 Symboles
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between Latin and Asian text, Don't adjust space between
Asian text and numbers
M quantités de mercure dans le premier piège d’amalgamation avec de l’or (µg)
A1,Hg
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between Latin and Asian text, Don't adjust space between
M quantités de mercure dans le second piège d’amalgamation avec de l’or (µg)
A2,Hg
Asian text and numbers
Formatted Table
CR,Hg concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
Formatted: Space Before: 3 pt, Don't adjust space
entre le porte-filtre et le tube plongeur de l’impinger contenant la solution de chlorure
between Latin and Asian text, Don't adjust space between
stanneux, ou l’entrée de l’unité de réduction catalytique, dans le cas d’un système de
Asian text and numbers
prélèvement sans ligne secondaire (μg/ml). Voir Figures 1 et 2.
Formatted: Left, Space Before: 3 pt, Don't adjust space
between Latin and Asian text, Don't adjust space between
C concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
R1,Hg
Asian text and numbers
entre le porte-filtre et la pièce en T, dans le cas d’un prélèvement avec ligne secondaire
Formatted: Space Before: 3 pt, Don't adjust space
(µg/ml). Voir Figure 3.
between Latin and Asian text, Don't adjust space between
Asian text and numbers
CR2,Hg concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
Formatted: Space Before: 3 pt, Don't adjust space
après la pièce en T jusqu’au tube plongeur de l’impinger contenant la solution de chlorure
between Latin and Asian text, Don't adjust space between
stanneux, ou l’entrée de l’unité de réduction catalytique, dans le cas d’un prélèvement avec Asian text and numbers
ligne secondaire (μg/ml). Voir Figure 3.
Formatted: Space Before: 3 pt, Don't adjust space
between Latin and Asian text, Don't adjust space between
Asian text and numbers
C concentration en mercure de la solution préparée pour l’analyse du mercure particulaire
S,Hg
(µg/ml) Formatted: Space Before: 3 pt, Don't adjust space
between Latin and Asian text, Don't adjust space between
Asian text and numbers
d masse volumique de la solution de réactif (g/ml)
Formatted
...
p pression atmosphérique (kPa)
atm Formatted: Font: Italic
Formatted
...
pav différence de pression moyenne entre le gaz entrant dans le compteur à gaz et l’atmosphère
Formatted
...
(kPa)
Formatted
...
qm,Hg flux massique du mercure exprimé en mercure élémentaire (mg/s) Formatted
...
Formatted
...
q débit-volume d’effluent gazeux au niveau de la section de mesurage dans les conditions i de
V,fg,i
Formatted
...
3
température, de pression, de teneur en vapeur d’eau et en oxygène (m /s)
Formatted
...
T température moyenne du gaz prélevé avant le compteur de gaz (K) Formatted
av
...
Formatted
...
3
u incertitude-type (μg/m )
(y)
Formatted
...
Formatted: Font: Italic
3
Vd volume de l’échantillon sec d’effluent gazeux normalisé dans les conditions NTP (m )
Formatted
...
3
V valeur finale affichée par le compteur à gaz à la fin du prélèvement (m )
f
Formatted
...
Formatted
...
V volume de l’échantillon sec d’effluent gazeux destiné à l’analyse du mercure gazeux,
G,d
Formatted
...
3
normalisé dans les conditions NTP (m )
Formatted
...
3
V valeur initiale affichée par le compteur à gaz au début du prélèvement (m )
i Formatted
...
Formatted
...
V volume d’air aspiré à travers le compteur à gaz pendant les essais intermédiaires
l
Formatted: Font: Italic
3
d’étanchéité (m )
Formatted
...
3
...
NORME ISO
INTERNATIONALE 21741
Première édition
2020-11
Émissions de sources fixes —
Échantillonnage et détermination
de la teneur en mercure dans les gaz
de combustion en utilisant un piège
d’amalgamation avec de l’or
Stationary source emissions — Sampling and determination of
mercury compounds in flue gas using gold amalgamation trap
Numéro de référence
ISO 21741:2020(F)
©
ISO 2020
---------------------- Page: 1 ----------------------
ISO 21741:2020(F)
DOCUMENT PROTÉGÉ PAR COPYRIGHT
© ISO 2020
Tous droits réservés. Sauf prescription différente ou nécessité dans le contexte de sa mise en œuvre, aucune partie de cette
publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique,
y compris la photocopie, ou la diffusion sur l’internet ou sur un intranet, sans autorisation écrite préalable. Une autorisation peut
être demandée à l’ISO à l’adresse ci-après ou au comité membre de l’ISO dans le pays du demandeur.
ISO copyright office
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Publié en Suisse
ii © ISO 2020 – Tous droits réservés
---------------------- Page: 2 ----------------------
ISO 21741:2020(F)
Sommaire Page
Avant-propos .v
Introduction .vi
1 Domaine d’application . 1
2 Références normatives . 1
3 Termes et définitions . 2
4 Symboles et termes abrégés . 2
4.1 Symboles . 2
4.2 Abréviations . 4
5 Principe . 4
6 Réactifs . 5
6.1 Généralités . 5
6.2 Eau . 5
6.3 Acide nitrique . 5
6.4 Acide sulfurique . 5
6.5 Solution de chlorure stanneux . 5
6.6 Solution tampon phosphatée . 5
6.7 Acide fluorhydrique . 6
6.8 Acide chlorhydrique . 6
6.9 Solution mère de mercure . 6
6.10 Solution de rinçage . 6
6.11 Agent de déshydratation du gaz prélevé. 6
6.12 Agent de piégeage du mercure . 6
7 Appareillage . 6
7.1 Généralités . 6
7.1.1 Système de prélèvement sans ligne secondaire . 7
7.1.2 Système de prélèvement avec ligne secondaire . 8
7.2 Buse . 9
7.3 Filtre et porte-filtre .10
7.4 Ligne de transfert.10
7.5 Unité de prétraitement.10
7.6 Piège d’amalgamation avec de l’or .11
7.7 Unité de séchage .11
7.8 Pompe de prélèvement .12
7.9 Thermomètre .12
7.10 Manomètre .12
7.11 Compteur à gaz .12
7.12 Débitmètre .12
7.13 Baromètre .12
8 Prélèvement .12
8.1 Généralités .12
8.2 Position et point de prélèvement .12
8.3 Durée de prélèvement et volume prélevé .13
8.4 Autres mesurages à effectuer avant le prélèvement.13
8.4.1 Débit-volume du gaz au niveau de la section de mesurage du conduit .13
8.4.2 Teneur en vapeur d’eau du gaz .13
8.4.3 Teneur en oxygène du gaz .13
8.5 Assemblage de l’appareillage de prélèvement .13
8.6 Prélèvement . .14
8.7 Contrôle d’étanchéité .14
8.8 Assurance de la qualité .14
8.9 Récupération de l’échantillon .15
© ISO 2020 – Tous droits réservés iii
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ISO 21741:2020(F)
8.10 Blanc de réactif .15
8.11 Blanc de site .16
9 Préparation de l’échantillon .16
9.1 Généralités .16
9.2 Préparation de l’échantillon en vue de l’analyse du mercure particulaire.16
10 Mode opératoire d’analyse .16
10.1 Mode opératoire d’analyse applicable au mercure collecté avec le piège
d’amalgamation avec de l’or .16
10.2 Mode opératoire d’analyse pour le mercure présent dans la solution de rinçage et
la solution digérée .18
11 Expression des résultats.18
11.1 Calcul du volume d’effluent gazeux sec prélevé dans les conditions de prélèvement .18
11.2 Calcul du volume de l’échantillon sec d’effluent gazeux normalisé en fonction
d’une température normale et d’une pression normale .19
11.3 Concentration massique de mercure gazeux dans l’effluent gazeux exprimé en
mercure élémentaire sur une base sèche et dans les conditions NTP .19
11.4 Concentration massique de mercure dans l’effluent gazeux exprimé en mercure
élémentaire, sur une base sèche, dans les conditions NTP et avec une teneur en
oxygène de référence .21
11.5 Flux massique du mercure exprimé en mercure élémentaire .21
11.6 Concentration massique de mercure de l’effluent gazeux exprimé en mercure
élémentaire sur une base humide dans les conditions NTP .22
11.7 Concentration massique de mercure de l’effluent gazeux exprimé en mercure
élémentaire de, sur une base humide dans les conditions NTP et avec une teneur
en oxygène de référence .22
12 Caractéristiques de performances .22
12.1 Limites de détection .22
12.2 Évaluation de l’incertitude de mesure .22
13 Rapport d’essai .23
Annexe A (informative) Préparation du mercure gazeux de référence .25
Annexe B (informative) Résultats de l’évaluation de l’incertitude de mesure .28
Annexe C (informative) Comparaison des résultats analytiques obtenus en utilisant
une unité de réduction catalytique chauffée et une unité de solution de chlorure
stanneux .30
Annexe D (informative) Comparaison des résultats analytiques obtenus en utilisant la
présente méthode et l’EN 13211 .32
Bibliographie .37
iv © ISO 2020 – Tous droits réservés
---------------------- Page: 4 ----------------------
ISO 21741:2020(F)
Avant-propos
L’ISO (Organisation internationale de normalisation) est une fédération mondiale d’organismes
nationaux de normalisation (comités membres de l’ISO). L’élaboration des Normes internationales est
en général confiée aux comités techniques de l’ISO. Chaque comité membre intéressé par une étude
a le droit de faire partie du comité technique créé à cet effet. Les organisations internationales,
gouvernementales et non gouvernementales, en liaison avec l’ISO participent également aux travaux.
L’ISO collabore étroitement avec la Commission électrotechnique internationale (IEC) en ce qui
concerne la normalisation électrotechnique.
Les procédures utilisées pour élaborer le présent document et celles destinées à sa mise à jour sont
décrites dans les Directives ISO/IEC, Partie 1. Il convient, en particulier de prendre note des différents
critères d’approbation requis pour les différents types de documents ISO. Le présent document a été
rédigé conformément aux règles de rédaction données dans les Directives ISO/IEC, Partie 2 (voir www
.iso .org/ directives).
L’attention est attirée sur le fait que certains des éléments du présent document peuvent faire l’objet de
droits de propriété intellectuelle ou de droits analogues. L’ISO ne saurait être tenue pour responsable
de ne pas avoir identifié de tels droits de propriété et averti de leur existence. Les détails concernant
les références aux droits de propriété intellectuelle ou autres droits analogues identifiés lors de
l’élaboration du document sont indiqués dans l’Introduction et/ou dans la liste des déclarations de
brevets reçues par l’ISO (voir www .iso .org/ brevets).
Les appellations commerciales éventuellement mentionnées dans le présent document sont données
pour information, par souci de commodité, à l’intention des utilisateurs et ne sauraient constituer un
engagement.
Pour une explication de la nature volontaire des normes, la signification des termes et expressions
spécifiques de l’ISO liés à l’évaluation de la conformité, ou pour toute information au sujet de l’adhésion
de l’ISO aux principes de l’Organisation mondiale du commerce (OMC) concernant les obstacles
techniques au commerce (OTC), voir le lien suivant: www .iso .org/ iso/ fr/ avant -propos.
Le présent document a été élaboré par le comité technique ISO/TC 146, Qualité de l’air, sous-comité SC 1,
Émissions de sources fixes.
Il convient que l’utilisateur adresse tout retour d’information ou toute question concernant le présent
document à l’organisme national de normalisation de son pays. Une liste exhaustive desdits organismes
se trouve à l’adresse www .iso .org/ fr/ members .html.
© ISO 2020 – Tous droits réservés v
---------------------- Page: 5 ----------------------
ISO 21741:2020(F)
Introduction
Les sources fixes telles que les installations de combustion à charbon, les fours de cimenterie, les
activités de fonderie de métaux non ferreux, les installations de calcination et les installations
d’incinération de déchets émettent du mercure. Il est donc de plus en plus important de contrôler les
émissions massiques de mercure des sources fixes afin de prévenir la pollution environnementale et les
effets néfastes du mercure sur la santé.
Le présent document décrit une méthode de prélèvement et de détermination des concentrations
en mercure des effluents gazeux dans les conduits ou émis en cheminées d’usine. Le mercure existe
0 2+
généralement sous forme élémentaire (Hg ) et oxydée (Hg ), à la fois en phase vapeur et en phase solide,
dans les effluents gazeux. Cette méthode permet de déterminer les concentrations totales en mercure
en phase vapeur et les concentrations totales en mercure en phase solide dans les effluents gazeux.
vi © ISO 2020 – Tous droits réservés
---------------------- Page: 6 ----------------------
NORME INTERNATIONALE ISO 21741:2020(F)
Émissions de sources fixes — Échantillonnage et
détermination de la teneur en mercure dans les gaz de
combustion en utilisant un piège d’amalgamation avec de
l’or
1 Domaine d’application
Le présent document décrit une méthode de prélèvement et de mesurage du mercure en phase vapeur
et en phase solide dans les effluents gazeux des sources fixes. Le mercure existe généralement sous
0 2+
forme élémentaire (Hg ) et oxydée (Hg ), à la fois en phase vapeur et en phase solide, dans les
effluents gazeux. Le mercure en phase vapeur (gazeux) est collecté par échantillonnage isocinétique
ou non isocinétique avec un piège d’amalgamation composé d’or après élimination du mercure en phase
solide (particulaire) à l’aide d’un filtre. Le piège d’amalgamation avec de l’or collectant uniquement
2+ 0
le mercure élémentaire gazeux, le mercure oxydé (Hg ) est converti en mercure élémentaire (Hg )
en phase vapeur, avant le piège d’amalgamation. La concentration en mercure gazeux est déterminée
par spectrométrie d’absorption atomique (AAS) ou par spectrométrie de fluorescence atomique (AFS)
après relargage du mercure par chauffage du piège d’amalgamation avec de l’or. Parallèlement, le
mercure particulaire est collecté par échantillonnage isocinétique sur un filtre et sa concentration est
déterminée par spectrométrie d’absorption atomique à vapeur froide (CVAAS) ou par spectrométrie de
fluorescence atomique à vapeur froide (CVAFS) après mise en solution du mercure particulaire.
La concentration totale en mercure dans l’effluent gazeux est exprimée sous forme de somme des
concentrations en mercure gazeux et en mercure particulaire.
La méthode d’amalgamation avec de l’or est destinée aux mesurages à court terme (périodiques) du
3 3
mercure gazeux dans une plage de concentration de 0,01 μg/m à 100 μg/m avec des volumes de
3 3
prélèvement compris entre 0,005 m et 0,1 m et un débit de gaz prélevé compris entre 0,2 l/min et 1 l/
3 3
min. La plage de mesurage du mercure particulaire s’étend généralement de 0,01 μg/m à 100 μg/m
3 3
avec des volumes de prélèvement compris entre 0,05 m et 1 m .
2 Références normatives
Les documents ci-après, dans leur intégralité ou non, sont des références normatives indispensables à
l’application du présent document. Pour les références datées, seule l’édition citée s’applique. Pour les
références non datées, la dernière édition du document de référence s’applique (y compris les éventuels
amendements).
ISO 3696, Eau pour laboratoire à usage analytique — Spécification et méthodes d'essai
ISO 9096, Émissions de sources fixes — Détermination manuelle de la concentration en masse de poussières
ISO 10396, Émissions de sources fixes — Échantillonnage pour la détermination automatisée des
concentrations d'émission de gaz pour des systèmes fixes de surveillance
ISO 12141, Émissions de sources fixes — Détermination d'une faible concentration en masse de matières
particulaires (poussières) — Méthode gravimétrique manuelle
ISO 12846:2012, Qualité de l'eau — Dosage du mercure — Méthode par spectrométrie d'absorption
atomique (SAA) avec et sans enrichissement
ISO 16911-1, Émissions de sources fixes — Détermination manuelle et automatique de la vitesse et du débit-
volume d'écoulement dans les conduits — Partie 1: Méthode de référence manuelle
© ISO 2020 – Tous droits réservés 1
---------------------- Page: 7 ----------------------
ISO 21741:2020(F)
ISO 17852:2006, Qualité de l'eau — Dosage du mercure — Méthode par spectrométrie de fluorescence
atomique
ISO 20988, Qualité de l'air — Lignes directrices pour estimer l'incertitude de mesure
3 Termes et définitions
Pour les besoins du présent document, les termes et définitions suivants s’appliquent.
L’ISO et l’IEC tiennent à jour des bases de données terminologiques destinées à être utilisées en
normalisation, consultables aux adresses suivantes:
— ISO Online browsing platform: disponible à l’adresse https:// www .iso .org/ obp
— IEC Electropedia: disponible à l’adresse http:// www .electropedia .org/
3.1
mercure gazeux
mercure existant à la fois sous forme élémentaire et oxydée, traversant un filtre ayant un rendement de
collecte d’au moins 99,5 % pour des particules de 0,3 μm de diamètre
3.2
mercure particulaire
mercure existant à la fois sous forme élémentaire et oxydée, contenu dans une particule en phase solide
captée par un filtre ayant un rendement de collecte d’au moins 99,5 % pour des particules de 0,3 μm de
diamètre
3.3
échantillonnage isocinétique
prélèvement effectué à un débit tel que la vitesse et la direction du gaz entrant dans la buse de
prélèvement sont les mêmes que celles du gaz dans le conduit au niveau du point de prélèvement (3.4)
3.4
point de prélèvement
position spécifique sur la section de mesurage au niveau de laquelle un échantillon est extrait
3.5
NTP
conditions normales de température (273,15 K) et de pression (101,325 kPa)
4 Symboles et termes abrégés
4.1 Symboles
M quantités de mercure dans le premier piège d’amalgamation avec de l’or (µg)
A1,Hg
M quantités de mercure dans le second piège d’amalgamation avec de l’or (µg)
A2,Hg
C concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
R,Hg
entre le porte-filtre et le tube plongeur de l’impinger contenant la solution de chlorure stan-
neux, ou l’entrée de l’unité de réduction catalytique, dans le cas d’un système de prélèvement
sans ligne secondaire (μg/ml). Voir Figures 1 et 2.
C concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
R1,Hg
entre le porte-filtre et la pièce en T, dans le cas d’un prélèvement avec ligne secondaire (µg/
ml). Voir Figure 3.
2 © ISO 2020 – Tous droits réservés
---------------------- Page: 8 ----------------------
ISO 21741:2020(F)
C concentration en mercure de la solution de rinçage ayant servi à rincer la ligne de transfert
R2,Hg
après la pièce en T jusqu’au tube plongeur de l’impinger contenant la solution de chlorure
stanneux, ou l’entrée de l’unité de réduction catalytique, dans le cas d’un prélèvement avec
ligne secondaire (μg/ml). Voir Figure 3.
C concentration en mercure de la solution préparée pour l’analyse du mercure particulaire (µg/ml)
S,Hg
d masse volumique de la solution de réactif (g/ml)
p pression atmosphérique (kPa)
atm
p différence de pression moyenne entre le gaz entrant dans le compteur à gaz et l’atmosphère (kPa)
av
q flux massique du mercure exprimé en mercure élémentaire (mg/s)
m,Hg
q débit-volume d’effluent gazeux au niveau de la section de mesurage dans les conditions i de
V,fg,i
3
température, de pression, de teneur en vapeur d’eau et en oxygène (m /s)
T température moyenne du gaz prélevé avant le compteur de gaz (K)
av
3
u incertitude-type (μg/m )
(y)
3
V volume de l’échantillon sec d’effluent gazeux normalisé dans les conditions NTP (m )
d
3
V valeur finale affichée par le compteur à gaz à la fin du prélèvement (m )
f
V volume de l’échantillon sec d’effluent gazeux destiné à l’analyse du mercure gazeux, normalisé
G,d
3
dans les conditions NTP (m )
3
V valeur initiale affichée par le compteur à gaz au début du prélèvement (m )
i
3
V volume d’air aspiré à travers le compteur à gaz pendant les essais intermédiaires d’étanchéité (m )
l
3
V volume de l’échantillon sec d’effluent gazeux (m )
m
V volume de l’échantillon sec d’effluent gazeux de la ligne principale, normalisé dans les condi-
principal,d
3
tions NTP, dans le cas d’un prélèvement avec ligne secondaire (m )
V volume de l’échantillon sec d’effluent gazeux prélevé pour l’analyse du mercure particulaire,
S,d
3
normalisé dans les conditions NTP (m )
V volume de l’échantillon sec d’effluent gazeux de la ligne secondaire, normalisé dans les condi-
secondaire,d
3
tions NTP, dans le cas d’un prélèvement avec ligne secondaire (m )
v volume récupéré de solution de rinçage ayant servi à rincer la ligne de transfert entre le
R
porte-filtre et le tube plongeur de l’impinger contenant la solution de chlorure stanneux, ou
l’entrée de l’unité de réduction catalytique, dans le cas d’un prélèvement sans ligne secondaire
(ml). Voir Figures 1 et 2.
v volume récupéré de solution de rinçage ayant servi à rincer la ligne de transfert entre le porte-
R1
filtre et la pièce en T dans le cas d’un prélèvement avec ligne secondaire (ml). Voir Figure 3.
v volume récupéré de solution de rinçage ayant servi à rincer la ligne de transfert après la
R2
pièce en T jusqu’au tube plongeur de l’impinger contenant la solution de chlorure stanneux,
ou l’entrée de l’unité de réduction catalytique, dans le cas d’un prélèvement avec ligne secon-
daire (ml). Voir Figure 3.
v volume de la solution préparée pour l’analyse du mercure particulaire (ml)
S
© ISO 2020 – Tous droits réservés 3
---------------------- Page: 9 ----------------------
ISO 21741:2020(F)
w teneur en vapeur d’eau moyenne de l’effluent gazeux au niveau de la section de mesurage
W
pendant la période de prélèvement (%)
ième 3
y j concentration du premier système de mesure (μg/m )
1,j
ème 3
y j concentration du second système de mesure (μg/m )
2,j
ρ concentration massique en mercure gazeux de l’effluent gazeux exprimé en mercure élémen-
G,Hg,sec
3
taire, sur une base sèche dans les co
...
SLOVENSKI STANDARD
oSIST ISO 21741:2021
01-februar-2021
Emisije nepremičnih virov - Vzorčenje in določevanje živosrebrovih spojin v
odpadnih plinih z amalgamacijo na zlatih pasteh
Stationary source emissions - Sampling and determination of mercury compounds in flue
gas using gold amalgamation trap
Émissions de sources fixes - Échantillonnage et détermination de la teneur en mercure
dans les gaz de combustion en utilisant un piège d’amalgamation de l’or
Ta slovenski standard je istoveten z: ISO 21741:2020
ICS:
13.040.40 Emisije nepremičnih virov Stationary source emissions
oSIST ISO 21741:2021 en,fr
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
---------------------- Page: 1 ----------------------
oSIST ISO 21741:2021
---------------------- Page: 2 ----------------------
oSIST ISO 21741:2021
INTERNATIONAL ISO
STANDARD 21741
First edition
2020-11
Stationary source emissions —
Sampling and determination of
mercury compounds in flue gas using
gold amalgamation trap
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en mercure dans les gaz de combustion en utilisant un piège
d’amalgamation de l’or
Reference number
ISO 21741:2020(E)
©
ISO 2020
---------------------- Page: 3 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH-1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Symbols and abbreviated terms . 2
4.1 Symbols . 2
4.2 Abbreviated terms . 4
5 Principle . 4
6 Reagents . 4
6.1 General . 4
6.2 Water . 5
6.3 Nitric acid . 5
6.4 Sulfuric acid . 5
6.5 Stannous chloride solution . 5
6.6 Phosphate buffer solution . 5
6.7 Hydrofluoric acid . 5
6.8 Hydrochloric acid . 5
6.9 Mercury stock solution . 5
6.10 Rinse solution . 5
6.11 Sample gas drying agent . 5
6.12 Trapping agent of mercury . 6
7 Apparatus . 6
7.1 General . 6
7.1.1 Main-stream sampling . 6
7.1.2 Side-stream sampling . 8
7.2 Nozzle. 9
7.3 Filter and filter housing . 9
7.4 Transfer line .10
7.5 Pretreatment unit .10
7.6 Gold amalgamation trap.11
7.7 Drying unit .11
7.8 Suction unit .11
7.9 Thermometer .11
7.10 Manometer .12
7.11 Gas meter .12
7.12 Flowmeter .12
7.13 Barometer .12
8 Sampling .12
8.1 General .12
8.2 Sampling position and sampling point .12
8.3 Sampling duration and sample volume .12
8.4 Other measurements to be made prior to sampling .13
8.4.1 Volumetric gas flow through duct at the sampling plane .13
8.4.2 Moisture content of gas .13
8.4.3 Oxygen content of gas .13
8.5 Assembly of sampling apparatus .13
8.6 Sampling .13
8.7 Checking for leaks .14
8.8 Quality assurance.14
8.9 Sample recovery .14
© ISO 2020 – All rights reserved iii
---------------------- Page: 5 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
8.10 Reagent blank.15
8.11 Field blank .15
9 Sample preparation .15
9.1 General .15
9.2 Sample preparation for particulate mercury analysis .15
10 Analytical procedure .16
10.1 Analytical procedure for mercury collected with gold amalgamation trap .16
10.2 Analytical procedure for mercury in rinse solution and digested solution .17
11 Expression of results .17
11.1 Calculation of the volume of dry flue gas sampled at sampling conditions .17
11.2 Calculation of the volume of dry flue gas sample normalized to standard
temperature and pressure .18
11.3 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP .18
11.4 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP and reference oxygen volume fraction .20
11.5 Rate of mass discharge of mercury expressed as elemental mercury .20
11.6 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP .20
11.7 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP and reference oxygen concentration .21
12 Performance characteristics .21
12.1 Detection limits .21
12.2 Evaluation of measurement uncertainty .21
13 Test report .22
Annex A (informative) Preparation of mercury reference gas .24
Annex B (informative) Results of evaluation of measurement uncertainties.27
Annex C (informative) Comparison of analytical results obtained with heated solid catalytic
reduction unit and stannous chloride solution unit .29
Annex D (informative) Comparison of analytical results obtained with this method and
EN 13211 .31
Annex E (informative) Interference from sulfur dioxide (SO ) on the recovery of elemental
2
mercury and oxidized mercury .33
Bibliography .35
iv © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,
Stationary source emissions.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
---------------------- Page: 7 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
Introduction
Because mercury is exhausted from stationary sources such as coal combustion plants, cement kilns,
non-ferrous metal smelting operations and roasting plants, and waste incineration facilities, the
monitoring of the stationary source mercury mass emissions is increasingly important for preventing
global environmental pollution and health damage caused by mercury.
This document describes a method for the sampling and determination of mercury concentrations
0
in a flue gas passing through ducts or chimney stacks. Mercury generally exists as elemental (Hg )
2+
and oxidized (Hg ) forms, both in vapour and in solid phases in flue gases, this method allows the
determination of both total vapour-phase mercury and total solid-phase mercury concentrations in
flue gases.
vi © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
oSIST ISO 21741:2021
INTERNATIONAL STANDARD ISO 21741:2020(E)
Stationary source emissions — Sampling and
determination of mercury compounds in flue gas using
gold amalgamation trap
1 Scope
This document describes a method for the sampling and measurement of mercury of both vapour and
0
solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg ) and
2+
oxidized (Hg ) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous)
mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after
removing solid-phase (particulate) mercury with a filter. Because gold amalgamation trap captures
2+
only gaseous elemental mercury, the oxidized mercury (Hg ) in the vapour phase is converted to
0
elemental mercury (Hg ) prior to the gold amalgamation trap. The concentration of gaseous mercury
is determined using atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS)
after releasing mercury by heating the gold amalgamation trap. Separately, particulate mercury is
collected isokinetically on a filter and the concentration is determined using cold vapour AAS or cold
vapour AFS after dissolving the particulate mercury into solution.
The total concentration of mercury in flue gas is expressed as the sum of both gaseous and particulate
mercury concentrations.
The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury
3 3 3 3
ranging from 0,01 μg/m to 100 μg/m with sampling volumes from 0,005 m to 0,1 m and sample gas
flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically
3 3 3 3
from 0,01 μg/m to 100 μg/m with sampling volume from 0,05 m to 1 m .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 9096, Stationary source emissions — Manual determination of mass concentration of particulate matter
ISO 10396, Stationary source emissions — Sampling for the automated determination of gas emission
concentrations for permanently-installed monitoring systems
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter
(dust) at low concentrations — Manual gravimetric method
ISO 12846:2012, Water quality — Determination of mercury — Method using atomic absorption
spectrometry (AAS) with and without enrichment
ISO 16911-1, Stationary source emissions — Manual and automatic determination of velocity and volume
flow rate in ducts — Part 1: Manual reference method
ISO 17852:2006, Water quality — Determination of mercury — Method using atomic fluorescence
spectrometry
ISO 20988, Air quality — Guidelines for estimating measurement uncertainty
© ISO 2020 – All rights reserved 1
---------------------- Page: 9 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
gaseous mercury
mercury existing both as elemental and oxidized forms passing through a filter having at least 99,5 %
collection efficiency for 0,3 μm diameter particles
3.2
particulate mercury
mercury existing both as elemental and oxidized forms contained in a solid phase particle collected by
a filter having at least 99,5 % collection efficiency for 0,3 μm diameter particles
3.3
isokinetic sampling
sampling at a flow rate such that the velocity and direction of the gas entering the sampling nozzle are
the same as those of the gas in the duct at the sampling point (3.4)
3.4
sampling point
specific position on the sampling section at which a sample is extracted
3.5
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Symbols and abbreviated terms
4.1 Symbols
M amounts of mercury in the first gold amalgamation trap (μg)
A1,Hg
M amounts of mercury in the second gold amalgamation trap (μg)
A2,Hg
C concentration of mercury in a prepared sample of rinse solution that washed the transfer
R,Hg
line from the filter housing to the impinger nozzle of stannous chloride solution or the inlet
of catalytic reduction unit in main-stream sampling (μg/ml). Ref. Figure 1 and 2.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R1,Hg
from the filter housing to the T-piece in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R2,Hg
after the T-piece to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample solution for particulate mercury
S,Hg
analysis (μg/ml)
d density of reagent solution (g/ml)
p atmospheric pressure (kPa)
atm
2 © ISO 2020 – All rights reserved
---------------------- Page: 10 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
p average pressure difference between the sample gas before the gas meter and the
av
atmosphere (kPa)
q rate of mass discharge of mercury expressed as elemental mercury (mg/s)
m,Hg
q volume flow rate of flue gas through the sampling plane at conditions i of temperature,
V,fg,i
3
pressure, moisture and oxygen content (m /s)
T average temperature of the sample gas before the gas meter (K)
av
3
u(y) standard uncertainty (μg/m )
3
V volume of dry flue gas sample normalized to STP (m )
d
3
V final gas meter reading at the end of sampling (m )
f
3
V volume of dry flue gas sample for gaseous mercury analysis normalized to STP (m )
G,d
3
V initial gas meter reading at the beginning of sampling (m )
i
3
V volume of air drawn through the gas meter during any intermediate leak tests (m )
l
3
V volume of dry flue gas sample (m )
m
V volume of dry flue gas sample in main stream, normalized to STP, in side-stream
main,d
3
sampling (m )
3
V volume of dry flue gas sample for particulate mercury analysis normalized to STP (m )
S,d
V volume of dry flue gas sampled in side stream, normalized to STP, in side-stream
side,d
3
sampling (m )
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R
housing to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in main-stream sampling (ml). Ref. Figure 1 and 2.
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R1
housing to the T-piece in side-stream sampling (ml). Ref. Figure 3.
v volume of a recovered sample of rinse solution that washed transfer line after the T-piece to
R2
the impinger nozzle of stannous chloride solution or the inlet of catalytic reduction unit in
side-stream sampling (ml). Ref. Figure 3.
v volume of a prepared sample solution for particulate mercury analysis (ml)
S
w average moisture content of the flue gas at the sampling plane during the sampling period (%)
W
3
y j th concentration value of the first measuring system (μg/m )
1,j
3
y j th concentration value of the second measuring system (μg/m )
2,j
ρ mass concentration of gaseous mercury expressed as elemental mercury in the flue gas on a
G,Hg,dry
3
dry basis at STP (μg/m )
ρ mass concentration of particulate mercury expressed as elemental mercury in the flue gas
S,Hg,dry
3
on a dry basis at STP (μg/m )
ρ mass concentration of total mercury expressed as elemental mercury in the flue gas on
Hg,dry
3
a dry basis at STP (μg/m )
© ISO 2020 – All rights reserved 3
---------------------- Page: 11 ----------------------
oSIST ISO 21741:2021
ISO 21741:2020(E)
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a dry
Hg,dry,O
3
basis at STP and reference oxygen concentration (μg/m )
ρ mass concentration of mercury expressed as elemental mercury at conditions i of
Hg,i
3
temperature, pressure, oxygen and moisture conditions (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet
3
basis at STP (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet,O
3
basis at STP and reference oxygen concentration (μg/m )
φ volume fraction of the oxygen on a dry basis me
...
FINAL
INTERNATIONAL ISO/FDIS
DRAFT
STANDARD 21741
ISO/TC 146/SC 1
Stationary source emissions —
Secretariat: BIS
Sampling and determination of
Voting begins on:
20200818 mercury compounds in flue gas using
gold amalgamation trap
Voting terminates on:
20201013
Émissions de sources fixes — Échantillonnage et détermination de la
teneur en mercure dans les gaz de combustion en utilisant un piège
d’amalgamation de l’or
RECIPIENTS OF THIS DRAFT ARE INVITED TO
SUBMIT, WITH THEIR COMMENTS, NOTIFICATION
OF ANY RELEVANT PATENT RIGHTS OF WHICH
THEY ARE AWARE AND TO PROVIDE SUPPOR TING
DOCUMENTATION.
IN ADDITION TO THEIR EVALUATION AS
Reference number
BEING ACCEPTABLE FOR INDUSTRIAL, TECHNO
ISO/FDIS 21741:2020(E)
LOGICAL, COMMERCIAL AND USER PURPOSES,
DRAFT INTERNATIONAL STANDARDS MAY ON
OCCASION HAVE TO BE CONSIDERED IN THE
LIGHT OF THEIR POTENTIAL TO BECOME STAN
DARDS TO WHICH REFERENCE MAY BE MADE IN
©
NATIONAL REGULATIONS. ISO 2020
---------------------- Page: 1 ----------------------
ISO/FDIS 21741:2020(E)
COPYRIGHT PROTECTED DOCUMENT
© ISO 2020
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting
on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address
below or ISO’s member body in the country of the requester.
ISO copyright office
CP 401 • Ch. de Blandonnet 8
CH1214 Vernier, Geneva
Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii © ISO 2020 – All rights reserved
---------------------- Page: 2 ----------------------
ISO/FDIS 21741:2020(E)
Contents Page
Foreword .v
Introduction .vi
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Clause title . 2
4.1 Symbols . 2
4.2 Abbreviated terms . 4
5 Principle . 4
6 Reagents . 4
6.1 General . 4
6.2 Water . 5
6.3 Nitric acid . 5
6.4 Sulfuric acid . 5
6.5 Stannous chloride solution . 5
6.6 Phosphate buffer solution . 5
6.7 Hydrofluoric acid . 5
6.8 Hydrochloric acid . 5
6.9 Mercury stock solution . 5
6.10 Rinse solution . 5
6.11 Sample gas drying agent . 5
6.12 Trapping agent of mercury . 6
7 Apparatus . 6
7.1 General . 6
7.1.1 Mainstream sampling . 6
7.1.2 Sidestream sampling . 8
7.2 Nozzle. 9
7.3 Filter and filter housing . 9
7.4 Transfer line .10
7.5 Pretreatment unit .10
7.6 Gold amalgamation trap.11
7.7 Drying unit .11
7.8 Suction unit .11
7.9 Thermometer .11
7.10 Manometer .12
7.11 Gas meter .12
7.12 Flowmeter .12
7.13 Barometer .12
8 Sampling .12
8.1 General .12
8.2 Sampling position and sampling point .12
8.3 Sampling duration and sample volume .12
8.4 Other measurements to be made prior to sampling .13
8.4.1 Volumetric gas flow through duct at the sampling plane .13
8.4.2 Moisture content of gas .13
8.4.3 Oxygen content of gas .13
8.5 Assembly of sampling apparatus .13
8.6 Sampling .13
8.7 Checking for leaks .14
8.8 Quality assurance.14
8.9 Sample recovery .14
© ISO 2020 – All rights reserved iii
---------------------- Page: 3 ----------------------
ISO/FDIS 21741:2020(E)
8.10 Reagent blank.15
8.11 Field blank .15
9 Sample preparation .15
9.1 General .15
9.2 Sample preparation for particulate mercury analysis .15
10 Analytical procedure .16
10.1 Analytical procedure for mercury collected with gold amalgamation trap .16
10.2 Analytical procedure for mercury in rinse solution and digested solution .17
11 Expression of results .17
11.1 Calculation of the volume of dry flue gas sampled at sampling conditions .17
11.2 Calculation of the volume of dry flue gas sample normalized to standard
temperature and pressure .18
11.3 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP .18
11.4 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a dry basis at STP and reference oxygen volume fraction .20
11.5 Rate of mass discharge of mercury expressed as elemental mercury .20
11.6 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP .20
11.7 Mass concentration of mercury expressed as elemental mercury in the flue gas on
a wet basis at STP and reference oxygen concentration .21
12 Performance characteristics .21
12.1 Detection limits .21
12.2 Evaluation of measurement uncertainty .21
13 Test report .22
Annex A (informative) Preparation of mercury reference gas .24
Annex B (informative) Results of evaluation of measurement uncertainties.27
Annex C (informative) Comparison of analytical results obtained with heated solid catalytic
reduction unit and stannous chloride solution unit .29
Annex D (informative) Comparison of analytical results obtained with this method and
EN 13211 .31
Annex E (informative) Interference from sulfur dioxide (SO ) on the recovery of elemental
2
mercury and oxidized mercury .33
Bibliography .35
iv © ISO 2020 – All rights reserved
---------------------- Page: 4 ----------------------
ISO/FDIS 21741:2020(E)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out
through ISO technical committees. Each member body interested in a subject for which a technical
committee has been established has the right to be represented on that committee. International
organizations, governmental and non-governmental, in liaison with ISO, also take part in the work.
ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of
electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are
described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the
different types of ISO documents should be noted. This document was drafted in accordance with the
editorial rules of the ISO/IEC Directives, Part 2 (see www .iso .org/ directives).
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of
any patent rights identified during the development of the document will be in the Introduction and/or
on the ISO list of patent declarations received (see www .iso .org/ patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to
the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see
www .iso .org/ iso/ foreword .html.
This document was prepared by Technical Committee ISO/TC 146, Air quality, Subcommittee SC 1,
Stationary source emissions.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www .iso .org/ members .html.
© ISO 2020 – All rights reserved v
---------------------- Page: 5 ----------------------
ISO/FDIS 21741:2020(E)
Introduction
Because mercury is exhausted from stationary sources such as coal combustion plants, cement kilns,
nonferrous metal smelting operations and roasting plants, and waste incineration facilities, the
monitoring of the stationary source mercury mass emissions is increasingly important for preventing
global environmental pollution and health damage caused by mercury.
This document describes a method for the sampling and determination of mercury concentrations
0
in a flue gas passing through ducts or chimney stacks. Mercury generally exists as elemental (Hg )
2+
and oxidized (Hg ) forms, both in vapour and in solid phases in flue gases, this method allows the
determination of both total vapour-phase mercury and total solid-phase mercury concentrations in
flue gases.
vi © ISO 2020 – All rights reserved
---------------------- Page: 6 ----------------------
FINAL DRAFT INTERNATIONAL STANDARD ISO/FDIS 21741:2020(E)
Stationary source emissions — Sampling and
determination of mercury compounds in flue gas using
gold amalgamation trap
1 Scope
This document describes a method for the sampling and measurement of mercury of both vapour and
0
solid phases on stationary source flue gas streams. Mercury generally exists as elemental (Hg ) and
2+
oxidized (Hg ) forms, both in the vapour and solid phases in flue gases. The vapour-phase (gaseous)
mercury is captured either isokinetically or non-isokinetically with a gold amalgamation trap after
removing solid-phase (particulate) mercury with a filter. Because gold amalgamation trap captures
2+
only gaseous elemental mercury, the oxidized mercury (Hg ) in the vapour phase is converted to
0
elemental mercury (Hg ) prior to the gold amalgamation trap. The concentration of gaseous mercury
is determined using atomic absorption spectrometry (AAS) or atomic fluorescence spectrometry (AFS)
after releasing mercury by heating the gold amalgamation trap. Separately, particulate mercury is
collected isokinetically on a filter and the concentration is determined using cold vapour AAS or cold
vapour AFS after dissolving the particulate mercury into solution.
The total concentration of mercury in flue gas is expressed as the sum of both gaseous and particulate
mercury concentrations.
The gold amalgamation method is intended for short-term (periodic) measurements of gaseous mercury
3 3 3 3
ranging from 0,01 μg/m to 100 μg/m with sampling volumes from 0,005 m to 0,1 m and sample gas
flow rate between 0,2 l/min to 1 l/min. The measurement range of particulate mercury is typically
3 3 3 3
from 0,01 μg/m to 100 μg/m with sampling volume from 0,05 m to 1 m .
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are
indispensable for its application. For dated references, only the edition cited applies. For undated
references, the latest edition of the referenced document (including any amendments) applies.
ISO 3696, Water for analytical laboratory use — Specification and test methods
ISO 9096, Stationary source emissions — Manual determination of mass concentration of particulate matter
ISO 10396, Stationary source emissions — Sampling for the automated determination of gas emission
concentrations for permanently-installed monitoring systems
ISO 12141, Stationary source emissions — Determination of mass concentration of particulate matter
(dust) at low concentrations — Manual gravimetric method
ISO 169111, Stationary source emissions — Manual and automatic determination of velocity and volume
flow rate in ducts — Part 1: Manual reference method
ISO 12846:2012, Water quality — Determination of mercury — Method using atomic absorption
spectrometry (AAS) with and without enrichment
ISO 17852:2006, Water quality — Determination of mercury — Method using atomic fluorescence
spectrometry
ISO 20988, Air quality — Guidelines for estimating measurement uncertainty
© ISO 2020 – All rights reserved 1
---------------------- Page: 7 ----------------------
ISO/FDIS 21741:2020(E)
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at http:// www .electropedia .org/
3.1
gaseous mercury
mercury existing both as elemental and oxidized forms passing through a filter having at least 99,5 %
collection efficiency for 0,3 μm diameter particles
3.2
particulate mercury
mercury existing both as elemental and oxidized forms contained in a solid phase particle collected by
a filter having at least 99,5 % collection efficiency for 0,3 μm diameter particles
3.3
isokinetic sampling
sampling at a flow rate such that the velocity and direction of the gas entering the sampling nozzle are
the same as those of the gas in the duct at the sampling point (3.4)
3.4
sampling point
specific position on the sampling section at which a sample is extracted
3.5
STP
standard conditions for temperature, 273,15 K, and pressure, 101,325 kPa
4 Clause title
4.1 Symbols
M amounts of mercury in the first gold amalgamation trap (μg)
A1,Hg
M amounts of mercury in the second gold amalgamation trap (μg)
A2,Hg
C concentration of mercury in a prepared sample of rinse solution that washed the transfer
R,Hg
line from the filter housing to the impinger nozzle of stannous chloride solution or the inlet
of catalytic reduction unit in main-stream sampling (μg/ml). Ref. Figure 1 and 2.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R1,Hg
from the filter housing to the T-piece in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample of rinse solution that washed transfer line
R2,Hg
after the T-piece to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in side-stream sampling (μg/ml). Ref. Figure 3.
C concentration of mercury in a prepared sample solution for particulate mercury
S,Hg
analysis (μg/ml)
d density of reagent solution (g/ml)
p atmospheric pressure (kPa)
atm
2 © ISO 2020 – All rights reserved
---------------------- Page: 8 ----------------------
ISO/FDIS 21741:2020(E)
p average pressure difference between the sample gas before the gas meter and the
av
atmosphere (kPa)
q rate of mass discharge of mercury expressed as elemental mercury (mg/s)
m,Hg
q volume flow rate of flue gas through the sampling plane at conditions i of temperature,
V,fg,i
3
pressure, moisture and oxygen content (m /s)
T average temperature of the sample gas before the gas meter (K)
av
3
u standard uncertainty (μg/m )
(y)
3
V volume of dry flue gas sample normalized to STP (m )
d
3
V final gas meter reading at the end of sampling (m )
f
3
V volume of dry flue gas sample for gaseous mercury analysis normalized to STP (m )
G,d
3
V initial gas meter reading at the beginning of sampling (m )
i
3
V volume of air drawn through the gas meter during any intermediate leak tests (m )
l
3
V volume of dry flue gas sample (m )
m
V volume of dry flue gas sample in main stream, normalized to STP, in side-stream
main,d
3
sampling (m )
3
V volume of dry flue gas sample for particulate mercury analysis normalized to STP (m )
S,d
V volume of dry flue gas sampled in side stream, normalized to STP, in side-stream
side,d
3
sampling (m )
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R
housing to the impinger nozzle of stannous chloride solution or the inlet of catalytic
reduction unit in mainstream sampling (ml). Ref. Figure 1 and 2.
v volume of a recovered sample of rinse solution that washed transfer line from the filter
R1
housing to the Tpiece in sidestream sampling (ml). Ref. Figure 3.
v volume of a recovered sample of rinse solution that washed transfer line after the Tpiece to
R2
the impinger nozzle of stannous chloride solution or the inlet of catalytic reduction unit in
sidestream sampling (ml). Ref. Figure 3.
v volume of a prepared sample solution for particulate mercury analysis (ml)
S
w average moisture content of the flue gas at the sampling plane during the sampling period (%)
W
3
y j th concentration value of the first measuring system (μg/m )
1,j
3
y j th concentration value of the second measuring system (μg/m )
2,j
ρ mass concentration of gaseous mercury expressed as elemental mercury in the flue gas on a
G,Hg,dry
3
dry basis at STP (μg/m )
ρ mass concentration of particulate mercury expressed as elemental mercury in the flue gas
S,Hg,dry
3
on a dry basis at STP (μg/m )
ρ mass concentration of total mercury expressed as elemental mercury in the flue gas on
Hg,dry
3
a dry basis at STP (μg/m )
© ISO 2020 – All rights reserved 3
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ISO/FDIS 21741:2020(E)
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a dry
Hg,dry,O
3
basis at STP and reference oxygen concentration (μg/m )
ρ mass concentration of mercury expressed as elemental mercury at conditions i of
Hg,i
3
temperature, pressure, oxygen and moisture conditions (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet
3
basis at STP (μg/m )
ρ mass concentration of mercury expressed as elemental mercury in the flue gas on a wet
Hg,wet,O
3
basis at STP and reference oxygen concentration (μg/m )
φ volume fraction of the oxygen on a dry basis measured during the sampling (%)
O, d
φ volume fraction of the reference oxygen for the process (%)
O, ref
4.2 Abbreviated terms
AAS atomic absorption spectrometry
AFS atomic fluorescence spectrometry
FEP Perfluoro(ethylene/propylene), tetrafluoroethylene/hexafluoropropylene
PFA perfluoroalkoxy alkane
PTFE polytetrafluoroethylene
5 Principle
In flue gases, mercury commonly exists in both the vapour phase and
...
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